Blog - Excursionset.comhttp://excursionset.com/blog/Thu, 19 Feb 2015 01:02:01 +0000en-USSite-Server v6.0.0-3508-3508 (http://www.squarespace.com)A Turning Lane As Lovely As A Tree? Richard EastherSat, 14 Feb 2015 12:14:54 +0000http://excursionset.com/blog/2015/2/15/modeling-traffic50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:54d74726e4b0ff7e52fb310fI recently blogged on the physics behind modelling traffic flow. This is not just an academic question for me, as the billion dollar Waterview Connection is a couple of kilometres from my house. The project involves the biggest road tunnels in Australasia, completes a key arterial connection in Auckland and is (surprisingly enough) coming in on time and on budget.

Waterview Connection [Russell Brown, publicaddress.net]

Waterview tunnel boring machine [Wikimedia]

Simultaneously, Auckland Transport is revamping a section of the Great North Road running parallel to the Northwestern Motorway, one of the roads being connected by the Waterview Connection. As part of this work, Auckland Transport wants to widen the road to make way for a short, additional turning lane at one intersection. There are a bunch of options for accomplishing this, but the one they chose requires felling six mature pohutukawa trees.

A broad coalition of people and organisations has sprung up in the trees' defence, including the local Board, a piece of city council itself as well as the city's own Parks Department. The trees are now festooned with signs, banners and a "yarn bomb", while thousands have joined the Save the Western Springs Pohutukawa group on Facebook and the trees themselves are tweeting. [The Lorax asked who would speak for the trees, but now it seems they can tweet for themselves.]

The pohotuKawa Six [facebook]

Since Auckland Transport's argument for felling the trees hinges on traffic models, I was keen to take a look at the modelling they used to settle on their "preferred option". Either my google-fu is weak or the detailed models are not in the public domain. That said, digging into the paperwork, I found "Appendix H", reviewing the analyses performed by Auckland Transport and its contractors, written by Leo Hills, an independent traffic engineer.

The first thing that struck me is that Appendix H is a tepid document. Its tone reminded me of an examiner's report for a thesis whose author has done the bare minimum to get by: the student may pass, but no-one involved will be proud. (Except possibly the student, of course.) It damns Auckland Transport's analyses with faint praise, queries the reasoning behind their choices, and points out that almost identical results could be obtained without removing the trees.

In other words, an independent analysis of Auckland Transport's own modelling comes well short of giving it a ringing endorsement.

Meanwhile, the New Zealand Ministry of Transport's Strategic Policy Programme has produced some fascinating reading (seriously – I know we are talking about traffic here, but it is great to see government departments sponsoring evidence-based research-driven thinking). One of the reports explores the forces shaping the future of transport in New Zealand. The study on projections of future demand is particularly illuminating:

TRansport projections for Light vehicle use against actual data for New Zealand; Ministry of Transport

Between around 1980 and 2004 vehicle-use grew by around 3% per year. In 2004, for whatever reason, this growth levelled off. What's more, per capita usage actually declines when you account for the population increase since then.

Despite this, assumptions about future usage patterns have repeatedly assumed that the steady rise was about to kick off again – look at the colourful sequence of rainbow lines attempting to find their way to the top-right corner. But so far, the real world and its real people in their real cars have refused to cooperate. This isn't a New Zealand-only quirk; similar trends have been observed world-wide, although the detailed causes vary from country to country. Simultaneously, public transport use in Auckland has increased and there is a growing focus on cycling, again in step with worldwide trends.

Putting all this together and looking at the trees, I have three big questions:

The traffic modelling behind Auckland Transport's analysis evaluates the design options for the intersection in terms of expected delays for westbound drivers (i.e. the people who benefit from the extra lane) in 2026; most of them during the evening commute. There is no mention of the uncertainty in the traffic projections that go into the models, either nationally or within the corridor defined by the Great North Road and adjacent motorway. However, going by recent history and the graphs above, if the numbers are wrong, they are likely to be too high, rather than too low. So what are the assumptions that go into the models, and do they depend on the sort of projections that have been wrong for a decade or more?

Leo Hills' report explicitly says that the modelling only considers the intersection itself, and not the overall network -- despite the large changes that can be expected once the Waterview Connection is complete. Nor is it clear what the model assumes about future public transport usage and cycling levels. So is the model simply too limited to capture the full behaviour of road users in 2026?

The "figure of merit" used to choose between design options is the delay-time for commuters on the Great North Road. However, if traffic jams form when the number of cars using a road passes a given tipping point, small changes in the number of cars on the road can cause disproportionately large changes in travel time. This magnifies the impact of assumptions about vehicle numbers going into the model. Do the models account for this? And, if so, how?

Putting all this together, it seems to me that while the traffic engineers have undoubtedly done their jobs when it came to constructing the models, the uncertainties related to the specification of the models are potentially huge. Consequently, I would love to see an open discussion of the modelling used by Auckland Transport to make this decision, and to know how they accounted for uncertainties in vehicle numbers and transport patterns.

I travel past the trees (sometimes by bike, sometimes by bus, sometimes by car) twice in each working day – I would hate to see them cut down over a piece of fuzzy math.

POSTSCRIPT: Full disclosure; my partner is a spokesperson for the Pohutukawa Savers, and I am (as usual) not speaking on behalf of my employer on this blog.

]]>Fire In The Sky...Richard EastherWed, 11 Feb 2015 22:54:08 +0000http://excursionset.com/blog/2015/2/12/fire-in-the-sky50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:54dbbc40e4b012c34eabcdd1New Zealand's North Island was treated to a spectacular fireworks display around 10pm last night, and reports are consistent with a large meteor or "space rock" hitting the earth's atmosphere. I missed it, but two people in my family saw a bright flash in the sky ("What on earth was that?" "Uh, dunno, what on earth was what?" said the resident scientist. Turns out it was something that was not on earth at all.)

Fireballs like last night's event are sometimes called bolides and the brightness, reported sonic booms and an explosion at altitude are all consistent with this class of events. Even so, this was a far smaller rock than the one that exploded above Russia (which I blogged about here). A study by Brown et al., published in Nature (420, 294-296, November 2002), found that hundreds of objects roughly half a metre in diameter and packing an energy equivalent to 100 tons of TNT hit the earth every year; last night's event would have been in this size range or a tad smaller. Really big events with an energy similar to the largest nuclear weapons ever tested occur much less often; maybe once every ten thousand years. (The rate of these really big, really rare events can be figured out from the number of rocks we see making a close pass to the earth, not by counting them as they happen.)

The plot below shows the distribution of big fireballs collated by a NASA study; if you look carefully just one of them sits squarely on top of New Zealand.

NASA study showing detected "fireball" events.

Bolides are like lotteries – the chances of you winning the big prize are small, but the chances that someone, somewhere will win are pretty good. So if you missed last night's fireball, you will wait a long time before seeing another one.

Reports that came in from a large part of the North Island suggest that the object was moving roughly north-south. Given that, there is a chance it was a piece of "space junk" rather than an actual meteor; many spacecraft move in orbits taking them from pole to pole. Objects in low earth orbit are routinely tracked from the ground, and if this was a piece of orbiting debris coming back to earth it was easily big enough that its absence will be obvious.

On the other hand, if this was a space rock it is likely to have been orbiting the sun since the birth of the solar system itself. For 4.6 billion years it led a largely uneventful existence, but the last few seconds of its lifetime were spectacular.

]]>The Sand ReckonerPhysicsSelfRichard EastherMon, 09 Feb 2015 00:53:39 +0000http://excursionset.com/blog/2015/2/9/the-sand-reckoner50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:54d09fcae4b04e76ff399fabDriving home one night last week, Auckland's Spaghetti Junction was more than normally congested and my thoughts turned to physics. Sluggish traffic let me follow my train of thought (an actual train would be a welcome option, but that's another story) without endangering my fellow road-users, as well as an initial topic; the differences between sand and water. Admittedly, many of these differences are obvious to anyone who visits a beach, but I was thinking about how sand sometimes flows like a liquid.

Anyone who has seen an old-fashioned egg timer knows sand can flow, but flowing sand is not the same as flowing water. If a hose is leaking from a pinprick, increasing the pressure makes the water flow faster. On the other hand, pressing down on sand flowing through a narrow funnel can cause the grains to lock together, stopping the flow entirely. The technical term for this is "jamming", which is how I got to be thinking about sand while sitting in traffic.

Simulation showing spontaneous jamming in a granular material.

Physicists often explain the properties of "granular materials" like sand by looking at interactions between adjacent grains. The same reasoning can be used with other systems – the complex movements of flocking birds are reproduced by boids, "birdoid-objects" that obey a few simple rules; avoid collisions but stay close to the flock...

Simulated starlings...

Just as scientists can explain the flocking of birds, we can also model the "flocking" of cars, exploring how patterns in traffic arise and dissipate. For instance, the videos below show an experimental traffic jam in Nagoya and a simulation from a group MIT, each capturing the same phenomenon:

A person stuck in traffic might wonder why scientists would want an artificial traffic jam, but figuring out how they form is a step towards preventing them. As a physicist, I was pleased (but not surprised) to see that both studies were published in physics journals – the Nagoya group published in the online New Journal of Physics while the MIT paper appeared in the Physical Review. And, just in case you are wondering, I looked these papers up after I had arrived home.

The MIT group treated traffic as if it was a fluid, but real vehicles are more like a flock of birds than water in a pipe. (OK, only to a physicist: car don't look much like birds OR liquids, but bear with me.) However, there are "agent models" or microsimulations that simulate the behavior of individual road users and the surprisingly lifelike scene below which includes vehicles sharing lanes (more common in places with lots of motorbikes or "tuk-tuks") was generated by an agent-based simulation:

A visualization of a PTV Vissim simulation featuring non-lane-based traffic. Different vehicles with a variety of widths interact with each other and find their way wherever there is enough space to fit.

The moral of this story, if it needs one, is that some science lies just beneath the irritation of city traffic and, for this physicist at least, contemplating it made a slow drive home pass more quickly.

POSTSCRIPT: The Sand Reckoner is the title of a short piece by Archimedes, where he works out the number of grains of sand the universe could hold. Physicists have been thinking about sand and the universe for a very long time.

]]>What the Spacecraft Saw In The Night...Richard EastherFri, 06 Feb 2015 02:39:14 +0000http://excursionset.com/blog/2015/2/6/what-the-dog-did-in-the-night50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:54d3d8c0e4b0846660f4911dGregory: Is there any other point to which you would wish to draw my attention?Holmes: To the curious incident of the dog in the night-time.Gregory: The dog did nothing in the night-time.Holmes: That was the curious incident.– From "Silver Blaze", Arthur Conan Doyle

Over the biggest science stories of the last year is the on-again, off-again discovery of gravitational waves left over from the Big Bang. But the biggest story in cosmology – one that has been building for 15 years – almost always flies under the radar. Since the year 2000, we have increased our stock of knowledge on the microwave background – fossil light from the Big Bang – by a factor of maybe 10,000. Likewise, our data on the distribution of galaxies in space has grown by between 10 and 100. Despite these advances, the "big picture" concordance cosmology describing the evolving universe has hardly changed at all.

Let me absolutely clear: this is good news for cosmologists. It means we can dig into the detailed history of the universe and test the two huge hypotheses which underpin the concordance cosmology – dark matter and dark energy. These are ad hoc assumptions (and profound challenges for theoretical physicists) but the predictions of the concordance model have survived a vast increase in our ability to test them.

When the first microwave background data from the Planck spacecraft was released in 2013 this pair of piecharts was part of the media package:

European space agency / Planck

The spin from the European Space Agency media team was that the estimated amounts of dark matter and "ordinary matter" in the universe had gone up, while the fraction of dark energy had dropped. To a cosmologist, this is interesting news. But the bigger story is that the two pies are very similar, with no slices added or subtracted, even though Planck had made huge strides in measuring the cosmos.

The next batch of Planck data was released yesterday (very early in the morning here in New Zealand), and this time the big news is that Planck has accurately measured how long it took for the first stars to light up after the Big Bang. The headline story is that the dark ages – the time before stars – lasted roughly 550 million years, 100 million years longer than Planck's previous estimate. (This is a long time, but a fraction of the 13.8 billion years since the Big Bang itself.)

Planck probes the dark ages because the first stars burn so brightly they ionise most of the gas in the primordial universe leaving a tell-tale imprint on the microwave background. However, this news adds confidence to the concordance cosmology as observations of distant galaxies are a better fit with this result than the previous estimate. If the gap hadn't narrowed, it might have looked as if some exotic process (decaying particles left over from the big bang?) helped to ionise the primordial universe – and many of these theories are now ruled out.

Sooner or later, there are bound to be surprises, even if we are back to square one when it comes to primordial gravitational waves. But just as Sherlock Holmes solved a mystery because a dog did not bark in the night, the biggest news today is what Planck does not say. To quote Holmes again, once once you eliminated the impossible, whatever remains, however improbable, must be the truth. So the concordance cosmology, with its dark energy and dark matter, is looking more and more like the truth, however improbable it might seem.

Postscript 1: Cosmologists could argue for ages over just how to measure the amount of information at our disposal and the numbers here are guesstimates. For the microwave background, the spectacular growth reflects our near-complete ignorance of its properties as little as 25 years ago, whereas 3D galaxy positions have been mapped for much longer. Either way, though, you can make a case that the storehouse of data used to test models of the evolving universe has a grown a million times bigger since the year 2000.

Postscript 2: The new Planck dataset has any number of interesting hints, and the key paper on inflation is still in preparation. I am still gathering my thoughts on that.

]]>Done and Dusted? PhysicsCosmologyAstronomyRichard EastherFri, 30 Jan 2015 20:38:27 +0000http://excursionset.com/blog/2015/1/31/done-and-dusted50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:54cb5dc4e4b03d93972e6f0fThe on-again off-again discovery of the "smoking gun of inflation" is now firmly set to "off". The latest development is an analysis combining data from the Planck spacecraft, the BICEP2 telescope at the South Pole (and the source of the original excitement) and the Keck Array, a second South Pole experiment. The announcement was supposed to come next week, but the news leaked yesterday when the Planck mission's French website put up the press release and background information early. The page is now locked, but rather pointlessly, given how fast the news spread. And while English is the (ahem) linga franca of science, monolingual Anglophones could get the gist from Google Translate.

The Planck announcement, today.

Back in March, the BICEP2 team claimed to have found a characteristic twist in the polarisation pattern of the microwave background -- fossil light from the big bang itself -- suggesting the universe was awash with gravitational waves. The most likely origin for these gravitational waves was inflation; a phase of accelerated expansion immediately after the Big Bang. The idea of inflaton has been around for 35 years, and the gravitational wave signal claimed by BICEP2 would convince most cosmologists inflation had really happened in our universe. The news turned the cosmology community on its head but slowly unravelled over the next few months.

Photons in the microwave background hail from the depths of intergalactic space, as they have been in flight since around 380,000 years after the Big Bang when the universe first becomes transparent. However, to get to us they pass through our Milky Way galaxy which contains a good deal of dust and gas. Some of the dust is electrically charged and interacts with the magnetic field of the galaxy, producing a similar pattern to the primordial gravitational wave signal. At the time the size of the dust signal was unknown, and the BICEP2 team accounted for it using the best estimates for its size. But those estimates were too conservative, and today's news is that the vast majority of their "signal" is from the dust.

The new information comes from combining observations at several different microwave frequencies. The map of the microwave sky made by BICEP2 is exquisitely clear, but uses a single frequency --150 gigahertz, about 1500 times higher than an FM radio signal -- so it is effectively black and white. The galactic dust has a different "colour" from the microwave background. The new analysis compares the BICEP2 signal to a map of sky made by the Planck satellite at 353 GHz and at this frequency dust is much brighter than the microwave background. If the BICEP2 looked different from the 353GHz Planck map,we would know that BICEP2 was not seeing a lot of dust - but the correlation between the maps is high, telling us that the BICEP2 signal is mainly dust and the champagne should have stayed in the fridge.

The new analysis does not rule out inflationary gravitational waves. The signal claimed by the BICEP2 team was always surprisingly large. Cosmologists use the variable "r" for the strength of a gravitational wave background. Before BICEP2 it seemed likely that r was smaller than 0.1, but the "headline" number from BICEP2 was r = 0.2, which dropped to r=0.16 when they subtracted their best-guess for the dust distribution. This table comes via Google Translate and the now hidden press release, and the upshot is that we are effectively back to where we were a year ago:

From the pLANCK WeB pAGE

That said, BICEP2 still represents a major milestone in our ability to probe the early universe; the technology it uses gives an exquisitely clear measurements, and we can expect huge progress on the observational side in the coming years.

When the news started to unravel, it struck me that the cosmology community was in the same position as someone waking up in an unfamiliar Las Vegas hotel room with a throbbing headache, hazy memories of the night before, and a fresh tattoo reading "r=0.2". So even if r is not exactly zero, it looks like we will need a visit to this guy:

Cosmologists, reacting to the latest BICEP2 news...

]]>Friends Don't Let Friends Do HStatisticsOpen ScienceRichard EastherThu, 29 Jan 2015 10:21:42 +0000http://excursionset.com/blog/2015/1/29/friends-dont-let-friends-do-h50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:54c9eabfe4b0fead1c1f5616When I recently wrote and tweeted about the increasing ubiquity of the h-index, almost no-one rose to its defence. It turns out that we all seemed to know that the h-index has only two real purposes. The first is penalising one-hit wonders (some of them Nobelists and Fields medalists) relative to reliable sloggers; the second is putting a fig leaf on crass comparisons of citation totals. And if we are honest with ourselves, we all know that the h-index is largely useless for anything else.

So my resolution for 2015 is this: I am going to go h-free, wherever possible. I won't use it in recommendations I write, I won't cite my own h-index in my annual performance appraisals, and I will discourage comparisons of h-indices when considering candidates for promotions, appointments and prizes.

Good scientists help set the direction for their fields, and that contribution is reflected in the citations they receive. But beyond the huge differences in collaboration styles and citation etiquette between subfields, there are many kinds of citations. A mention like "Following the work of Guth [REF 1]" means far more than being embedded in a long list like "Recent work includes [REF 2 - REF 27]", but citation counting treats both cases equally. Scientists are creative, and I am sure it is possible to design metrics that measure the worth of citations. But I am equally sure that these metrics won't be created just by adding epicycles to h.

Postscript: I am grateful to Alexander Yong for pointing me to the previous discussions of the correlation between the h-index and citation counts. And, if I had to guess as to how a useful metric of scientific impact might be built, I would look to sophisticated analyses of citation graphs (in the technical sense) and machine-based natural language parsing, but both approaches are intrinsically more nuanced than the h-index.

]]>Measurer, Measure Yourself. Richard EastherTue, 20 Jan 2015 12:12:09 +0000http://excursionset.com/blog/2015/1/19/measurer-measure-yourself50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:54baec1de4b07b4a7d184e12The great Russian physicist, Lev Landau used to rank physicists on a scale from 0 to 5. The better you were, the smaller your number. Newton alone was a 0, Einstein scraped in at 0.5, and founders of quantum mechanics like Bohr and Planck were 1s. Landau rated himself a 2.5 which he bumped up to a 2 after winning the Nobel Prize. Grade inflation was not a concern with Landau -- for him, the vast majority of professional physicists were mundane 5s.

Landau constructed his list for his personal enjoyment, but scientists must frequently judge their colleagues: for hiring, promotions, awarding prizes and fellowships, parceling out grants, and ofr "Research Assessments" of one sort or another. And since scientists are scientists many algorithmic ranking schemes have been proposed, spinning off the sub-discipline of bibliometrics.

The basic coin of science is the published paper. These are easy to count, but that doesn't help much on its own: the brutal truth is that many research papers are of little interest to anyone but their author and possibly the author's proud parents. The next level is tallying citations: how often one article is referred to by other articles. Good scientists have an impact on the work of other scientists and citations reflect that influence. But there are caveats: good papers may be overlooked, while papers which are annoyingly wrong gather multiple mentions in articles refuting them. And not all citations are equal: you can spend a career churning out "fast followups",looking busy while doing little to advance the field.

Beyond counting papers and citations, the h-index, proposed by Jorge Hirsch is 2005, is by far the most popular ranking tool. The h-index reduces the output of a scientist (or several scientists) to a single number: "h" is the number of papers you have written with h or more citations. Clearly, the bigger your h, the better you look.

In the decade following its invention the h-index has become ubiquitous and Google Scholar and major academic databases will compute it for you. The h-index is simple and yet feels "science-y', so it is tempting to use it as a stand-in for nuanced judgement.

However, the h-index is only meaningful if it contains information you couldn't learn from just counting citations and papers. Right off the bat, your h-index can't be larger than the total number of papers you have written. And it must be smaller than the square root of your citation count, since it says you have h papers, each with at least h citations. But you can get fancier. Alexander Yong at UIUC did a lovely analysis of the h-index, deriving a rule of thumb that says an h-index is likely to be around half of the square root of the total citation count. (Yong models the h-index via partitions, the number of different ways a number can be chopped into sums of integers - it is a lovely piece of work.)

Yong's plots his guesstimated h-index against the actual value for a group of mathematicians, and the match is pretty good:

From Yong, Bulletin of the AMS 61 1040 (2014) Used with permission.

Ranking scientists by their citation count seems simplistic -- if we were happy doing that there would have no real need to invent the h-index. However, if the h-index is pretty close to the square root of the citation count, comparing h-indices is not toodifferent from comparing citation counts and we are back to square one.

The h-index has been on my mind because I seem to be seeing it more and more frequently on academic CVs. Given that the h-index is easily computed from public data there is no profound reason not to provide it yourself, but the other day I found myself asking on Twitter

In some professions and countries it is common to include a photo on your CV, although this practice is fortunately rare in the sciences. That said, most scientists have a significant Google footprint and you will be googled, so when you are ranking applicants you are likely to see their photos. Like photos, h-indices are easy to find, but my feeling is neither photos nor h-indices have any place on a CV. The h-index is a very blunt instrument and by volunteering your h-index you are tacitly acceding to its use in the hiring process.

And if we are using h-indices to rank colleagues and potential colleagues perhaps we should also think again, and make sure that we understand what the h-index is actually measuring.

Postscript: The corollary of Yong's result is that the h-index is most interesting when the rule of thumb fails. The h-index was designed to penalise people with a single highly cited paper, but a one-hit wonders can still win the Nobel Prize -- for example, Peter Higgs of the Higgs boson was quiescent for vast majority of his career, and his h-index is smaller than that of some PhD students.

]]>No Rose Without a ThornOpen ScienceBad ScienceRichard EastherTue, 13 Jan 2015 22:15:06 +0000http://excursionset.com/blog/2015/1/14/no-rose-without-a-thorn50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:54b598f1e4b0adb56c391fc1In the last few years the number of "open access" journals has burgeoned. Open access journals are free to read, which limits their ability to raise money from subscriptions, and they typically charge authors a fee for publication. This may sound a little odd, but "page charges" are standard at many traditional journals. That said, this business model creates a challenge: set your standards too high and you won't be able to meet your payroll; set them too low and you won't be taken seriously by the scholarly community.

Open access also creates opportunities for scammers who are happy to sit at the bottom of the food chain. The phenomenon is known as "predatory open access", and a handy list of possible bucket-shop operators is available online. Predatory journals prey on those who are too naive to realise what is going on, or are either vain or venal enough to pay to see their name on a "published" article and I get spam every day from these outfits asking for submissions. They really do publish pretty much anything in return for money, as the authors of a paper entitled "Get Me Off Your &*^#ing Mailing List" discovered last year (although they didn't actually say &*^#) when they tried to stem the flow of email from predatory journals.

I normally just ignore these entreaties, but over the last few weeks, "AshEse Visionary" popped up more than once in my inbox. I accidentally clicked on the link, and found this:

http://www.ashese.co.uk - downloaded January 14, 2015.

After learning that this journal will "work with Arthurs every step of the way" I couldn't resist digging deeper, despite not being an Arthur myself.

Surfing around their site, it struck me that their "instructions for authors" page was very clear and well-written. Who wrote it is far less obvious though, as googling a few key phrases turns up the same text in a slew of places. Looking at the first few pages of hits, almost all of them are on the list of possible predatory journals, or look as if they should be.(In fact, does using this content indicate that you should be on the list?)

And it has to be said that Ashese has strict ethical guidelines for its authors, even if these do bear a striking resemblance to those of the journal Brain, as you can see from the following samples:

Ashese
Brain
Ashese
Brain

I am still a huge fan of open science, despite the barrage of pay-to-play spam, and would love to live in a world where all scholarly publications were freely available to anyone who wants to see them. But I am beginning to think we need peer review for journals, as much as we need it for the articles within them.

]]>Winning BronzeNew ZealandPhysicsRichard EastherTue, 11 Nov 2014 13:04:35 +0000http://excursionset.com/blog/2014/11/11/winning-bronze50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:54615d1ae4b0efbe9431deb6Sir Robert "Bob" Jones is New Zealand's answer to Donald Trump; a wealthy property investor with a sideline as an internet and old-media troll, albeit with a better barber than The Donald. In yesterday's Herald Jones shares his opinions on which New Zealanders merit a bronze statue, and the list is very short. By Jones's reckoning, the only truly great New Zealander is Sir Edmund Hillary, who conquered Everest, crossed the Antarctic and then devoted his later life to building schools and hospitals in Nepal.

Scientists will be pained to see that Jones wrote off physicist Ernest Rutherford's claim to greatness:

Ernest Rutherford, who’s on our $100 banknotes [...] is unknown beyond the physics world, his accomplishments being largely a team effort.

Jones is dead wrong here. It was Rutherford who figured out that atoms have a central nucleus and a cloud of electrons, one of the biggest discoveries in human history. And while Rutherford led a decent-sized team of scientists at Cambridge, it was a small crew compared to the 400 people in the 1953 Everest expedition that put Hillary on top of Everest.

Earlier in his career, Rutherford was based at McGill University, in Montreal. While he was in Canada, Rutherford showed that radioactivity leads to the transmutation of one chemical element into another, as close as nature gets to the dreams of the alchemists. I visited McGill in the Fall of 2011, and made a small pilgrimage to the Rutherford museum inside its Department of Physics, which contains much of Rutherford's experimental apparatus. Looking at my photos from that trip, "huge team" is not the first phrase that springs to mind.

If physicists get an afterlife, Rutherford will no doubt be smiling at Jones's comments: he had little time for people pretending to know more than they actually do. And on the bright side, Jones sees more $100 bills than most of us, so he will have plenty of opportunities to reflect on our famous compatriot.

In fact, Rutherford is already immortalised in bronze, near his childhood home of Brightwater - apparently Jones was not asked for permission. (And, if a "scientist as kid" statue-meme went viral, I would not be at all unhappy.)

Wikimedia

Rutherford died at Cambridge and is buried in Westminster Abbey a few yards from Isaac Newton; a much rarer honour than a mere Nobel. Given that Rutherford showed us so much about how the world really works, Christopher Wren's famous epitaph – si monumentum requiris circumspice – might also serve for Rutherford:

Today, another chapter has been added to the increasingly convoluted BICEP2 saga [see here, here, here and here for my accounts of previous developments]. The story began on March 21st with a media conference heard around the world that heralded a "5 sigma" detection of gravitational waves in the polarisation patterns in the microwave sky. This was presented as prima facie evidence our universe began with an inflationary phase that created these patterns a few trillionths of a trillionth of a trillionth of a second after the Big Bang itself.

Unfortunately, once the initial excitement died away, a number of voices asked whether BICEP2's signal had a more humble origin -- dust in our own galaxy. Dust can mimic a gravitational wave signal if it interacts with the galaxy's magnetic field. From a cosmic perspective, anything inside our galaxy is a "foreground" – dirt on the window through which we peer at the microwave background, the fossil light from the big bang coming to us from the furthest reaches of space. And however amazing ‘space dust’ sounds, it is a lot less exciting to a cosmologist than hard evidence of gravitational waves.

BICEP2 is a specialised device -- it looks at one patch of the sky in a single frequency, forming an exquisitely detailed but monochromatic map of that subset of the heavens. By contrast, the European Space Agency's Planck spacecraft observed the full sky in multiple frequencies, but with less clarity than BICEP2. Tantalisingly, much of the Planck data is still "in the can" as the Planck Science Team works to extract useful and reliable information from the torrent of observations captured by the spacecraft. Planck's frequency coverage means it can predict the amount of dust BICEP2 should expect to see, even though it cannot match the pinpoint clarity of the BICEP2 measurement itself.

Which brings us to yesterday: Planck scientists posted a preprint estimating the amount of dust in the BICEP2 field of view. The results are discouraging for anyone hoping the original BICEP2 announcement would survive.

This is the first time since the original BICEP2 announcement that genuinely new data has been added to the analysis, so it is a big step toward a full understanding.

If the new Planck dust analysis had been available to the BICEP2 team in March, they would presumably not have confidently claimed a detection of the "B-mode", the hallmark of an inflationary gravitational wave signal.

Even if dust does not contribute all of the B-mode seen by BICEP2, any inflationary gravitational wave signal is likely to be significantly smaller than the number reported in the original BICEP2 analysis. This is not too surprising, as that value was hard to reconcile with other, indirect constraints on inflation.

The actual BICEP2 observations still represent a stunning technical achievement and marked a huge leap forward in our ability to measure the microwave background; the debate here is around the interpretation, not the observations themselves.

The original BICEP2 estimate for the dust signal matched the broad expectations of the community, but the dust (and particularly its contribution to the polarisation) had not been well observed, and the Planck results now suggest that those expectations were overly optimistic.

It ain't over till it's over. The new Planck analysis is itself an extrapolation from high frequencies (where the dust is more visible) to the single frequency observed by BICEP2 (where the gravitational wave signal would be most obvious), so there is plenty of room for further surprises. What is needed now is a direct comparison between BICEP2 and the full Planck dataset -- that is in the works, and could bring another twist to the tale.

Finally, there is a real risk that cosmology bloggers and science magazine sub-editors will run out of ideas for slightly melancholy dust-related headlines…

As the euphoria around the original BICEP2 announcement faded a few months ago, I said that the mood amongst cosmologists was (I imagined!) not unlike that of someone slowly waking up in an unfamiliar Las Vegas hotel room with a throbbing headache, hazy memories of the night before, and a fresh tattoo reading "r=0.2". And just as Johnny Depp found it necessary to make minor amendments to his "Winona Forever" ink, cosmologists will be thinking that "r=0.?" might better express our feelings for the time being.

]]>Reaction ShotBad SciencePhysicsRichard EastherTue, 05 Aug 2014 12:43:56 +0000http://excursionset.com/blog/2014/8/5/reaction-shot50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:53e09a95e4b07b43013e5a37As Mark Twain apparently didn't say, a lie can travel half way around the world while the truth is still putting its boots on. And when that lie is powered by a breakthrough, NASA-approved space drive technology it can get to infinity and beyond, even if the truth is in hot pursuit.

In fairness, this is not a story about a lie, but a poorly-described experiment mixed with credulous journalism. Four days ago, a piece on Wired.co.uk described a breakthrough reactionless drive -- a closed box that could move entirely on its own without ejecting any "reaction mass" or otherwise interacting with its surroundings. These staples of science fiction are in the same category as perpetual motion machines -- but rather than breaking the laws of thermodynamics, reactionless drives violate Newton's Third Law, which says that every action much have an equal and opposite reaction.

Newton's Laws have survived all challenges (after a generalisation to accommodate relativity) for 350 years. Everything in science is one experiment away from being wrong. However, while thousands of scientists and backyard inventors have claimed to find loopholes in Newton but not one has stood up to scrutiny. Consequently anyone claiming to have built a reactionless drive should be treated with caution, unless they arrive at their press conference in a flying car.

Immediately after the Wired story, a posse of scientists pulled it apart. Sean Carroll called it "sub-Star-Trek-technobabble" and mathematical physicist John Baez gave it a thorough fisking. The whole kerfuffle was caused by a conference presentation from a group of NASA scientists and engineers of which which only the abstract is online. Amazingly, this abstract says they ran tests for both the "drive" and a "control" that was not supposed to work – and both of them "worked". But instead of worrying that this meant that the tiny effects they saw were due to some subtle experimental difficulty, they simply declared victory. Extraordinary claims require extraordinary evidence, but by any reasonable standard this experiment failed to demonstrate that the drive worked. Not even NASA can polish a turd, but it seems they know how to roll them in glitter.

XKCD.COM

Many people are "wrong on the internet", but there is a bigger picture here. NASA has an astonishing grip on the public imagination. Long after the moon landings, I regularly meet kids who dream of "working for NASA" and its profile far exceeds that of other excellent Federal science organisations such as NIST or the CDC. Consequently it is painful to see NASA's reputation being squandered, and the group behind this performance was also responsible for last year's warp drive fiasco (which I blogged about here and here).

This might seem like an academic debate, but NASA's apparent endorsement of fringe science can cause real harm. There is a veritable ecosystem of misguided enthusiasts and outright hucksters who peddle "breakthrough technologies" flying in the face of established physics, and NASA's imprimatur will help them soak the gullible and the optimistic.

Meanwhile the rest of us need a NASA that speaks with authority on climate and the environment, and can secure support for its otherwise excellent science programme – and this cannot help.

]]>Dust to DustNew ZealandPhysicsSelfRichard EastherWed, 02 Jul 2014 11:00:57 +0000http://excursionset.com/blog/2014/7/2/stock-photo-soup50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:53b1e1b3e4b03d7c53db1ebdThe equation-filled blackboard is one of the most reliable props of academia, not just in cartoons and movies, but in real life. You know a scientific discussion is taking a turn for the serious when the protagonists head to the board. Walking into a colleague's office, a glance at the scrawled notes on their board gives you a taste of their current research preoccupations and teaching commitments; wobbly chalk drawings along the bottom edge are a pretty good sign that the office's owner has a small child in their life. Blackboards are found in the corridors of academe as well as the offices and classrooms. And at the Isaac Newton Institute for Mathematical Sciences in Cambridge, every bathroom stall has a small chalkboard, just to be on the safe side.

I've got blackboards on the mind because they have been popping up in my Facebook feed over the last few days, thanks to this advertisement for something called Creative Physics 5.0:

Those Ivy League Professors can certainly keep a secret; I spent most of the last 20 years in Ivy League physics departments and never once saw Creative Physics, nor that many young men in full jacket and tie. But in my patch of ivy, blackboards were certainly ubiquitous.

Where I work now, though, whiteboards rule the roost, and I find myself missing the timbre of chalk on slate, and even the chalkdust on my fingers. So when this one popped up on my screen, I couldn't help taking a closer look. It sports an authentic palimpsestic underlay of previous scribblings, a couple of nifty plots, a trig function or two, and a liberal sprinkling of superscripts (n, 2, and the ambiguous o) that always give a blackboard a sophisticated look. It's great to see the lemniscate get an outing here, too, even if the equation in which it guest-stars doesn't add up to much.

Best of all is the triangle, whose internal angles total 90 degrees rather than the conventional 180. Good old non-Euclidean geometry.

A Google image search reveals that this is a stock photo, so the creators of Creative Physics are responsible merely for selecting it, not for its eccentricities. (Good news: "stock-photo-blackboard consultant" is clearly a vacant niche for an enterprising physics student.)

But select it they did. There's a pleasant irony in promoting a computer-based learning system with an image of an ancient piece of hands-on edu-tech. You'd think the blackboard's cultural stock would be on the wane; chalkboards conjure images of lecturers transcribing old notes while standing with their back -- literally and metaphorically -- to the class. In a world where students download snippets of instruction from Khan Academy, the chalkboard could look like a dusty relic.

But on a good day, "the board" conjures a momentary collaborative community. There's a shared, dynamic connection when a talented teacher takes a stick of chalk and walks a class through an argument in real time, duster and all. Physicists often speak of performing a calculation, and in the right hands the chalk and the board can be magical.

Personally, i am enormously excited by the plethora of new tools for teaching physics (or indeed any subject) -- e.g. MOOCs, flipped classrooms or studio physics. But just as movies, radio, TV and YouTube did not spell the end of live concerts and theatre, I suspect the live lecture will keep a place in the academy, as will the good old board, whether black or white.

And for fans of ivy covered professors in ivy covered halls, here's some Tom Lehrer...

]]>Schooling Colin CraigRichard EastherSun, 22 Jun 2014 11:14:32 +0000http://excursionset.com/blog/2014/6/22/climate50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:539d7d40e4b068ee91ecca8aIf nine year olds went to university, our lecture theatres would be crammed with would-be astronomers and astrophysicists. I visited a primary school last week and pretty much every hand in the room was up for over an hour. Topics ranged from why we have daytime and nighttime through to black holes and galaxies. The kids didn't run out of concentration or curiosity and a bunch of them stayed on into their break to ask more questions; the morning ended when a teacher gently persuaded them to let me grab a cookie in the staffroom. I think I had as much fun as the kids - an amazingly diverse group - and their inquisitive intelligence and excellent teachers boosted my confidence in the future.

Last week I also blogged about New Zealand politician Colin Craig, and his willingness to give serious consideration to loopy conspiracy theories (cough -- moon landings -- cough), while confidently displaying his ignorance of some really basic science. As I wrote, Craig goes far beyond the standard hedging used by politicians who want to put off grappling with climate change ("it's complex", "the jury is still out", "scientists disagree", "I'm not a scientist"), and apparently believes that it is not even possible for human behaviour to significantly modify the climate. For instance, here is "Colin's Comment" from a Conservative party pamphlet

Human impact on climate is so small it is nothing compared to a single volcanic eruption or a sun spot. We simply do not fully understand the long term cycles at work in the world.

The Keeling Curve -- the annual cycle is due to plants extracting more CO2 from the atmosphere during the northern hemisphere growing season; the overall trend is in black.

This increase in atmospheric CO2 levels is roughly consistent with world-wide fossil-fuel consumption (some carbon gets converted to biomass, while some is absorbed by the oceans, a source of concern in its own right), and its anthropogenic origin is not seriously disputed. Secondly, we've known for over a century that CO2 is a "greenhouse gas" and that it has an impact on climate. Yes, CO2 is not the only greenhouse gas, but human beings are twiddling with one of the knobs that controls the earth's climate system.

The key debate is about climate sensitivity, that is, how the climate will change (and how fast it will change) as we change the amount of CO2 in the atmosphere. It's complicated, and scientists are throwing themselves at the problem with alacrity. But Craig isn't talking about sensitivity: taking his words at face value, he flatly denies that it is even possible for our species to meaningfully affect the climate. Even among denialists, that's an extreme stance.

This is not Craig's only foray into climate science -- in April he was described as saying that "whether the sun has a hot day or a cold day 'is by far the biggest influence' on the Earth's climate". I'm not even sure where to start with that deep confusion between weather and climate, except to say it'll be a cold day in hell when the sun has a 'cold day'.

Craig doubles down on this remarkable hot-and-cold solar theory in an interview with the University of Otago student magazine Critic:

The major influence, in my view, and far away the biggest influence on us is our sun. I mean, it’s the biggest influence on our climate, seasons, climate change and effect, because we’re slightly a different distance away from the sun.

Dear me. Some of the nine-year-olds I spoke to last week could teach Craig a thing or two. Yes, the sun is key to our climate, but that's not the point -- this is about climate change. Seasons are not due to being us "slightly a different distance away from the sun" -- if that was true, the northern and southern summers would happen at the same time. Rather, [Hello Rooms 10, 11 and 12!) the earth's tilted axis causes seasons: the hemisphere tipped toward the sun has longer days and shorter nights, leading to a phenomenon technically known as "summer". (Maybe Craig is trying to say this in his own words, but they're not very clear.)

If Craig is talking about earth's varying proximity to the sun, our planet's elliptical orbit brings it closest to the sun in December -- but worldwide average temperatures usually peak in August, when we are close to our maximum distance from the sun. This comes about because land warms more quickly than ocean, and there is more land in the top half of the world than the bottom. Beyond being a nice snippet of science, it reminds us that "common sense" doesn't get you far with something as complicated as the climate system. It is true that the earth's track round the sun can change over thousands and millions of years as we are gently tugged this way and that by the other planets. (Is this what Craig is talking about, with his "slightly a different distance"? I have no idea). However, anthropogenic climate change is happening over decades, a relative eye-blink compared to the long-term cycles that govern the movement of the planets.

One more example. The Conservative Party's website has a section called "Your Questions Answered", in which someone (Craig, presumably) answers a query about climate change as follows:

1. Climate change happens for many reasons. Geological events (volcanoes) and astological [sic] events (Sun flares) to name but 2 have a large influence. Fluctuation of the natural environment and temperature is normal.

2. Man made carbon generation and other human activity does have an influence on temperature locally. Stand on an asphalt pavement in the middle summer and compare this to standing in an open field and you get the point.

— http://www.conservativeparty.org.nz/index.php?page=FAQ

The volcanoes are back again, but with added "astological" spice, suggesting that Craig's understanding of astronomy is at about the same level as his ability to spell it. Again, where to start. Solar flares (if that's what he means by "sun flares") are transient events with little or no long-term impact on the climate system. I am scratching my head about the asphalt pavements -- possibly he's referring to the notion that urban heat islands could bias long-term land-based temperature datasets, a claim that was definitively rebutted by the Berkeley Earth re-analysis of global temperature records.

I could go on, but it gets to be like shooting fish in a barrel. Taken as a whole, Craig's thinking on climate science is about as reality-based -- and as useful to New Zealand -- as the belief that milk bottles will hatch into baby calves if you leave them in a warm cupboard for a couple of weeks.

Craig's lack of detailed scientific knowledge is not unusual. My school visit reminded me that the average nine-year-old is often more actively engaged with science than the average adult, and even if you once knew exactly how many moons Jupiter had and why the seasons change, the details may have become a little hazy over time. There's no shame in that; grown-ups have many things on their minds. The problem lies in not acknowledging or even seeing the limits of one's understanding. Colin Craig is confidently campaigning on a policy that mixes profound misconceptions about basic science with hand-me-down climate-sceptic talking points. This, together with his willingness to entertain crazy conspiracy theories, should be of concern both to voters and to his potential coalition partners.

]]>He's not a scientist...Richard EastherSun, 15 Jun 2014 21:08:33 +0000http://excursionset.com/blog/2014/6/15/conservative50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:53086166e4b0e23db628041eIn the United States, right wing politicians who want to gain the approbation of the lunatic rump of the Republican party while preserving their credibility with moderate voters have taken to sidestepping climate questions with the phrase "I'm not a scientist". In New Zealand a similar "that's above my pay grade" strategy has been adopted by Colin Craig, a businessman turned politician, although the questions he dodges with it are a little different.

For instance, faced with a query about chemtrails in the "Ask Colin" of his Conservative Party's website, Craig admits to being "aware of the theory that chemicals are being released at high altitude for some nefarious purpose" but has a bob each way by adding "[I] don't know whether there is any truth in this or not." Likewise, asked about the reality of the moon landings by a journalist, Craig hedged again: he is "inclined to believe" they happened but "know[s] there are very serious people that question these things."

Everyone has their limit, though, and Craig's is the Reptilian hypothesis: he tells an interlocutor that he "can’t subscribe" to the claim that the world is secretly run by blood-drinking, shape-shifting reptilian humanoids from the Alpha Draconis star system. Craig follows this slightly tepid repudiation by saying "I hold a position similar to Carroll Quigley" who, as Craig explains, believed that the wealthy run the world for their own benefit. However, Craig does not mention Quigley's belief that "secret societies" help shape global events, which made him a favourite with conspiracy theorists, nor that he is revered by the far-right John Birch Society. (Even if you haven't heard of the Birchers, you might know them by the way their fluoride obsession was memorably parodied in Peter Sellers' Dr Strangelove.) Now, I am certainly not implying that Craig shares the peculiar beliefs of the John Birch Society, but an enthusiastic endorsement of Quigley is an interesting choice for someone rejecting a conspiracy theory.

But there is one topic on which Craig doesn't hedge at all. He is 100% bet-the-farm-on-it confident in his judgement on the complexities of climate change. Here's an answer on the subject from "Ask Colin":

1. Climate change happens for many reasons. Geological events (volcanoes) and astological [sic] events (Sun flares) to name but 2 have a large influence. Fluctuation of the natural environment and temperature is normal.

2. Man made carbon generation and other human activity does have an influence on temperature locally. Stand on an asphalt pavement in the middle summer and compare this to standing in an open field and you get the point.

3. However globally our influence on temperature is very very small. New Zealand's influence is infinitesimally small.

Let's skip over Craig's mixing of astronomy and astrology, his proofreading, and his tenuous grip on the jargon (what is a "sun flare"?). Here he is, loud and proud, taking a firmer stance on global warming than he did on moon landings or chemtrails or even shape-shifting reptiles, happily embracing a position at odds with mainstream scientific and popular opinion. No wishy-washy "I'm not a scientist" talking points for Craig here; he definitively states that human activity does not and cannot affect the global climate.

Why is he so sure? What has he been reading? Who does he talk to? Did he dig into the literature himself? What due diligence did he perform in order to write off much of modern climate science more confidently than he rejects wacky conspiracy theories?

Craig points to an 8-page pamphlet that outlines the Conservative Party's stance on climate. Disappointingly, it doesn't explain how their heterodox policy was arrived at. However, perhaps we can find other places where the same sentiments are expressed. For instance, the pamphlet includes a story about Canute, under the headline "We could all learn from this...":

Conservative Party pamphlet.

On first read, the story feels a little pre-digested, and sure enough a quick Google search reveals that tale is told in almost exactly the same words in William Bennett'sBook of Virtues. We could all learn from this that it's important to cite your sources. (By the bye, I'm not sure a story about a king who couldn't stop the sea rising works as a parable about the follies of climate alarmism, but let's press on.)

Exploring further, the pamphlet also contains a helpful climate quiz:

Conservative Party pamphlet.

Several of the questions and answers are uncontroversial -- yes, C02 makes up 0.04% of our atmosphere, yes we would miss the greenhouse gases (including water vapour) if they vanished, and yes the pre-industrial climate was far from constant. Others are carefully worded -- whether "nearly all" scientists agree on climate change depends on the definition of "nearly all" -- and on the whole, the overall quiz reads like a pencil and paper push poll.

In this case, googling for key phrases turns up Global Warming: Ten Facts and Ten Myths on Climate Change by Robert M Carter. Ignoring minor editorial changes, Questions 7-10 (and perhaps bits of the others) are amongst Carter's facts and myths. In particular, the phrases "[N]early all scientists agree that it [climate change] is occurring, and at a dangerous rate", "The Kyoto Protocol will cost many trillions of dollars [...] but will deliver no significant cooling", "Prior to the industrial revolution the Earth had a stable climate" and "Carbon dioxide [...] the primary forcing agent for temperature increase" are found in both Craig's quiz and Carter's "facts and myths".

Robert Carter is a New Zealander now resident in Australia, and a Fellow of the Royal Society of New Zealand. Carter is also a fairly well-known "climate skeptic", and was a member of the New Zealand Climate Science Coalition. Both Carter and the coalition were reportedly funded by the Heartland Institute, which turned to climate skepticism after its previous business model -- denying the links between tobacco smoke and cancer -- became unsustainable. These "myths" have not been peer-reviewed, and paint a picture at odds with the global consensus on climate science.

Carter's "myths" can be found on many websites (and given the New Zealand connection, the Conservatives may have got them directly from Carter himself) but if you search for them on Google the first hit is a 2009 posting on GlobalResearch, which also has a fair bit on chemtrails and a full range of other wacky conspiracy theories.

When asked about his potential coalition partner's apparent flirtation with conspiracy theories, Prime Minister John Key wondered if Craig was "winding up" the media by dropping hints about chemtrails. Possibly Craig's patter is simply a dog-whistle to kooky potential supporters (which is not particularly attractive, but it wouldn't be the first time a politician had done it) but if it is a wind-up, it is certainly a very thorough one.

Given the current state of the New Zealand electorate, Craig's party stands a chance of being part of a coalition government. It is worth asking how did the Conservative Party arrive at its positions? Who did it consult? Where does it stand on evidence-based policy-making? Perhaps we should "Ask Colin"?

Postscript: And if you haven't seen Dr Strangelove, hurry to the video store or the internets.

]]>Let's Do The Space Warp Again...Bad SciencePhysicsRichard EastherFri, 13 Jun 2014 05:06:59 +0000http://excursionset.com/blog/2014/6/13/lets-do-the-space-warp-again50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:539a53d8e4b05782d59b9724Just under a year ago the internet cranked out dozens of stories on NASA's efforts to develop "warp drive" technologies. And just under a year ago, dozens of scientists and science bloggers explained that while Einstein's general theory of relativity let's you describe a warp drive, that doesn't mean that the universe will let you build one. I blogged about it, as did many others.

The pictures are undeniably cool, but they are more fiction than science. The NASA project is being led by "Sonny" White, and involves something called a White-Juday interferometer. I did a back of the envelope calculation last year, and couldn't see how White's claims stacked up, nor has the interferometer been described in a peer-reviewed paper. (And looking back, my analysis was over-generous by a factor of trillions, since I assumed that the system had a kilogram worth of "negative mass matter", a preposterously large amount for any lab-based setup.) Conversely, I am not aware of a single reputable scientist who takes this project seriously.

Rademaker himself appears to have worked pro bono, but NASA is spending tax dollars on this project (not a lot, but some) at a time when real missions are being cut. However many hits this generates, NASA is squandering reputational credit on junk science and serious outlets are running this clickbait as news without applying even the most cursory of sniff-tests. I wish it wasn't true.

]]>BICEP2; redux redux CosmologyOpen SciencePhysicsStatisticsRichard EastherSat, 24 May 2014 23:27:09 +0000http://excursionset.com/blog/2014/5/25/bicep2-one-more-thing50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:537b4ab1e4b016f3beb0c7dfWhen the news of the BICEP2 result broke, the mood was euphoric. There was open speculation about Nobel Prizes, a certain video went viral and cosmologists spoke of a radical transformation in our understanding of the early universe. And all of this may still come to pass. But the wave of doubt blowing through the cosmological community in the last week is growing into a consensus that the BICEP2 team has overstated the case for a discovery. (For recent coverage see Science Magazine, Scientific American and the Washington Post.)

BICEP2 squeezes information from the cosmic microwave background, light that has been flying across the universe since just after the Big Bang, forming the backdrop against against which we view the rest of the cosmos. Isolating and removing other sources of microwaves -- so-called "foregrounds" -- is a key challenge for all observers of the microwave sky.

Crucially, BICEP2 measures both the intensity and polarisation of the microwave sky, and the polarisation of foregrounds is poorly understood. After two months of scrutiny, there is a realisation that the BICEP2 team may have underestimated the polarisation contribution from the dust in our galaxy and, in addition, was overly optimistic about the quality of their foreground estimate. Consequently, it seems that the BICEP2 team cannot confidently claim to have detected a "primordial B mode", the signature of gravitational waves and the hallmark of an inflationary era in the early universe.

A further twist is that the BICEP2 foreground analysis relied on unreleased data from the Planck satellite, "scraped" from preliminary maps shown at conferences and preserved in PDFs of the speakers' slides. My initial reaction to this was fairly tolerant, but it really was not (and never will be) a good idea. Specifically, scraping itself adds uncertainty, and this uncertainty was not quantified or accounted for by the BICEP2 team. Moreover, preliminary data is preliminary: the measured value shown at any point in a map of the microwave sky is effectively the difference between two much larger and almost equal numbers, but if either of these quantities changes slightly (as the calibration of the instrument improves, for instance), their difference can change substantially -- another source of uncertainty that the BICEP2 error budget ignored. Finally, the data-scraping detracts from the BICEP2 observations themselves, which represent a dramatic advance in our ability to measure the microwave sky. Astrophysics is a poster-child for the Open Science movement, but this moment is a reminder of the distinction between open science and other people's unfinished work.

So where does this leave us? These developments do not rule out the possibility of a large gravitational wave background, and the data needed to understand the foregrounds is currently being gathered and analysed. If our universe does turn out to contain a significant gravitational wave background, BICEP2 will undeniably have participated in its discovery. Conversely, if the signal seen by BICEP2 is shown to consist entirely of foreground, that heartwarming viral video may come to look like an episode of Candid Camera in which not even the host was in on the joke. And for now, cosmologists are living in interesting times.

]]>BICEP2: Two Months Later (and the Morning After)CosmologyOpen ScienceRichard EastherMon, 19 May 2014 10:52:05 +0000http://excursionset.com/blog/2014/5/19/bicep2-two-months50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:5376c589e4b0aefc671d38b8It's two months since the BICEP2 team announced it had seen the fingerprints of gravitational waves in the microwave background, thus apparently opening a portal into the universe ten trillion, trillion, trillionths of a second after the Big Bang. In the last week, however, the mood among cosmologists has taken on a morning-after tone, with a wave of doubt rolling through the community. It's possible that the cosmology community is slowly waking up to find itself in an unfamiliar Las Vegas hotel room with a throbbing headache, hazy memories of the night before, and a fresh tattoo reading "r=0.2".

What's the issue?

The second thoughts are about how the BICEP2 analysis accounts for "foregrounds", which is to say, things between us and what we're looking at. In this case, the question is: how might dust in our own galaxy interfere with the detection of tell-tale signs of gravitational waves in the microwave sky?

The BICEP2 team concluded that foregrounds contribute around 20% of their signal, which leaves plenty of room to make a confident claim to have detected gravitational waves.

By far the best way to isolate foreground dust is to use the microwave equivalent of a colour photo – but unfortunately the BICEP2 image is monochromatic. Consequently, the BICEP2 team could not extract foregrounds using just their own data. Instead, they presented a slate of indirect methods, in order to arrive at a reasonable estimate. One of these approaches uses the Planck satellite's measurements of the microwave sky, and it's this one that has come in for serious scrutiny.

Firstly, it's become clear that the BICEP2 team snagged the data they needed – which has not been formally released by the Planck collaboration – from a "teaser" image in a presentation posted online. This is certainly unorthodox, but does not immediately undermine the BICEP2 result. The issue burst into the public domain when Dan Falkowski (who often discusses -- and disseminates -- particle physics rumours on his blog Resonaances) not only drew attention to the "data-scraping", but claimed that the BICEP2 team had misinterpreted the images and would be revising their paper.

The BICEP2 people hotly denied they had made a mistake, and didn't even concede there was a mistake to argue about.

Separately, in a talk at Princeton (see video and slides), Raphael Flauger presented a virtuoso re-analysis of the foregrounds, including an estimate of the extra uncertainty injected by the fact that information was grabbed from a PDF file rather than from raw data. His measured conclusion was that the BICEP2 result is possibly overly optimistic.

So Where Are We Now?

This is not (yet) a show-stopper, but the debate shines a light on a weak spot in BICEP2's claim to have seen the fingerprints of gravitational waves.

In the long run, we need more data. Planck data was only part of the BICEP2 team's estimation of the foregrounds, and new data (being gathered as you read this) should provide a much better answer over the next 12 months.

Is This How Science is Done Now?

Apparently, yes it is. This is science in the age of the internet, and the world gets to watch in real time. We are caught between two powerful forces -- on the one hand, as Lyman Page (a Princeton astrophysicist and microwave background expert) says at the end of Flauger's talk:

So this is not – we all know, this is not sound methodology. You can’t bank on this, you shouldn’t. [...] You just can’t, you can’t do science by digitizing other people’s images.

But on the other hand, does anyone really expect us just to sit and wait?

As far as the screen-scraping is concerned, there are precedents -- a few years ago, the Pamela satellite was rumoured to have seen an excess of high energy positrons in cosmic rays that might have been due to dark matter in our galaxy. The Pamela team showed a slide at a conference and a couple of enterprising individuals snapped photos and extracted the datapoints -- hundreds of papers quickly followed. Given the cameras that live inside our phones, the ubiquity of video at big conferences, these days "teasers" effectively amount to an unofficial data release. So people who drop hints about unpublished results in conference talks while coyly flashing a visual aid should not be surprised at the consequences. [As it turns out, the Pamela excess is real, but can explained by less glamorous mechanisms than dark matter].

One might also ask why Planck doesn't just release the sky map used by BICEP2 and be done with it. That's because what they showed was a work-in-progress: maps like this are not "raw" data, but the end-product of a long and painstaking analysis, and we can't demand that anyone turn over a half-finished product.

As many people have pointed out, the BICEP2 results have not gone through peer review. On the other hand, many other people (including me) also pointed out that over the last two months the BICEP2 papers have been dissected by hundreds of scientists, so they are getting more stringent, open-air scrutiny than any journal could provide (given that important journal papers might still only go past three referees). Moreover, many recent announcements (Planck, WMAP, the Higgs) were made before undergoing peer review, so this is the new normal. (It follows the near ubiquitous practice among the astro-and particle physics communities of posting full "preprints" on arxiv.org before you send your article to an actual journal.)

The Worst-Case Scenario

Whatever happens, the BICEP2 observations are by far the most precise measurements of the microwave background ever made. Even if the claimed detection of gravitational waves evaporates, the technological strides that underpin BICEP2 (and similar experiments now gathering data) will bring dramatic progress in cosmology. Even in the worst-case scenario, we are not looking at a re-run of the faster-than-light neutrinos flap which was traced to a loose cable and a dodgy clock and became entirely uninteresting once those problems were solved.

My Own Guess

Personally, I would not be surprised if BICEP2 had overestimated the strength of the gravitational wave signal, even if I am not expecting it to vanish completely when the dust has settled (if you will pardon the pun). Cosmologists use the parameter "r" to describe the strength of the gravitational wave background. Before BICEP2, indirect measurements suggested that r was no more than 0.1, but BICEP2 prefers a higher number. A higher value of r would be fantastic for me and my fellow theorists, but it almost seems too good to be true.

On the other hand, if BICEP2 is correct, it successfully probes the universe at energies a trillion times higher than we can reach at the LHC. Any intuition we might claim to have about physics at these scales is tenuous at best, so we will simply have to wait and see what develops.

So even if the honeymoon is over, cosmology and gravitational waves are not yet headed for a Vegas-style quickie divorce. On the other hand, perhaps they need a restorative breakfast at the hotel buffet and a heart-to-heart about where they go from here. (And they may yet need some touch-ups on that tattoo).

Live from New York City

If you are in Auckland on May 31 (or in New York City on May 30, when you can see it in the flesh) the University of Auckland is partnering with New York's World Science Festival to present a simulcast of a Festival programme on the BICEP2 results, Ripples from the Big Bang. Moderated by Brian Greene it brings together John Kovac, one of the leaders of BICEP2, Alan Guth and Andrei Linde, who played key roles in the development of inflation, microwave background experimentalist Amber Miller, and Princeton theorist Paul Steinhardt. The New York event will be streamed live followed by a local Q&A, with me providing the Answers. Free entry, but ticket required for entry.

]]>BICEP2: A Month LaterAstronomyCosmologyNew ZealandOpen ScienceSelfPhysicsRichard EastherThu, 17 Apr 2014 01:42:39 +0000http://excursionset.com/blog/2014/4/17/bicep2-a-month-later50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:534b283fe4b072e1d4f09dd1A month ago the BICEP2 team announced that our universe is apparently awash with gravitational waves, pointing to the existence of an inflationary phase moments after the Big Bang. This was front page news all over the world, and cosmologists and astrophysicists have been working overtime to make sense of the news. Here is some of that sense...

Let The Ambulance Races Begin

For theoretical physicists, ambulance chasing involves getting papers out quickly after a major data release. Some ambulance chasers make significant contributions, some are just trying to draw attention to their earlier work, while others are banging out insubstantial papers in the hope that they will be cited by their slower colleagues. But whatever their motives, cosmologists have certainly been busy: the BICEP2 discovery paper has been cited 188 times on the Arxiv, all in "preprints" written within a month of the original announcement. I am pretty sure this is a world record, and you can always check the current tally.

In fairness, though, cosmologists were so giddy about BICEP2 it wouldn't have surprised me if someone had stolen an ambulance and driven it in circles, flashing the lights and letting rip with the siren.

Distributed Peer Review and Open Science

Once upon a time, the right way to announce a big result was to 1) write the paper, 2) send it to a journal, wait for it to be 3) peer reviewed and 4) accepted for publication, after which you could 5) hold a press conference. However, like most recent announcements in fundamental physics and cosmology, BICEP2 went straight from paper to media event, skipping steps 2, 3 and 4.

Old-timers will shake their heads, but this approach fits the principles of open science, which advocates making the processes and products of science transparent and widely available. Given that 1000 scientists are now scrutinising the BICEP2 results, rather than just two or three readers appointed by a journal, this amounts to an intensive, distributed and open peer review process, which is no bad thing. (And the papers will end up in a journal sooner or later.)

Trouble in Paradise?

The real gold-standard for science is not peer review but reproducibility. BICEP2 claims to have detected a specific twist in the polarization of the microwave background -- the so-called "B-mode". This detection will not be a sure thing until it is confirmed by an independent team with an independent instrument performing an independent analysis. On top of that, inflation is not the only possible origin of such a B-mode, and further data will help confirm the theoretical interpretation of the BICEP2 observations.

The good news is that no-one has found any show-stoppers. The biggest worry to surface so far is probably that the patch of sky BICEP2 observed may be contaminated by emission from radio "loops" associated with our own galaxy. It is not clear to me that this signal would necessarily reproduce the BICEP2 result, but unsubtracted foregrounds are likely to make any underlying gravitational wave signal look bigger than it really is, and that will need careful checking. And in the worst-case scenario, the BICEP2 results would be purely due to foregrounds, or some other analytical glitch.

We may not have to wait long. The BICEP2 team will be looking closely at these concerns, and more data will be gathered during the coming polar night. In addition, the Planck satellite has gathered the world's most comprehensive observations of the microwave background and their science team is extending their initial analysis to look at polarization, with results promised before the end of 2014.

Free Trips to Stockholm

If the BICEP2 result is verified, it is certain to attract the attention of the Nobel committee. In fact, it may be worth two Nobel prizes – one for the idea of inflation, and one for the detection of B-modes, which is a technological tour de force in its own right. (Two prizes have already gone to the microwave background -- one for its discovery, and one for the first mapping of the temperature of the microwave background.)

Speculating about "the prize" is a popular game among scientists, and I have already heard people ruminate about the likely judgment of history if it turns out that the BICEP2 analysis is basically correct but slightly dust-contaminated. In this scenario, the BICEP2 announcement would have been made with far more confidence than the data ultimately justified, which would provide conversational fodder for decades.

The intellectual history of inflation has many parallels with that of the the Higgs boson; they are both elegant hypotheses that existed for decades before being experimentally confirmed (assuming, again, that BICEP2 really has seen evidence of inflation). And like the Higgs, the theoretical parentage of inflation is murky. Alan Guth is undoubtedly the Peter Higgs of inflation (even if it is not called "the Guth phase"), but a number people made key contributions to the development of the theory. Unfortunately, only three of them can share the Prize, and there will be discreet (and probably blatant) lobbying for the other two places on the stage if the BICEP2 data holds up.

What I Have Been Doing?

Beyond giving a slew of interviews the day the story broke, my group at the University of Auckland (in collaboration with Kevork Abazajian at UC Irvine) has looked carefully at the apparent tension between BICEP2 and existing cosmological data. BICEP2 does not just claim to have seen gravitational waves, but to have seen gravitational waves with an amplitude which was apparently ruled out by previous analyses.

We crunched a lot of numbers very quickly, thanks to the high performance computing facilities at NeSI (New Zealand's e-research organization), and showed that this tension between BICEP2 and previous analyses is statistically significant. Consequently, taking all currently available astrophysical datasets at face value, BICEP2 appears to tell us three startling things about the early universe:

Inflation really did happen right after the big bang.

Inflation happened when the energy density of the universe was very high, as the strength of the gravitational wave background depends directly on the energy density of the universe during inflation. This means that the mechanism of inflation can give us a portal into the realm of ultra-high energy physics, where we expect candidate "grand unified theories" (including string theory) to be important.

The inflationary phase must be relatively complex, for the gravitational wave background to have escaped indirect analyses made prior to BICEP2. And this means that cosmologists will be able to make far more stringent tests of competing inflationary models than we might have expected.

Alternatively (and much more conservatively!) our results could suggest that the BICEP2 team has over-estimated the strength of the gravitational wave background and that future analyses will remove this discrepancy.

One More Thing

To me, one of the most astonishing things about the BICEP2 telescope is just how small it is. The secret to BICEP2 is not its size, but the exquisitely sensitive superconducting transition edge sensors used to detect the microwave signal. Admittedly, BICEP2 sits at the South Pole, the whole instrument is chilled to within a hair's-breadth of absolute zero (a major technological and logistical challenge) and it is surrounded by a complex array of shields, but the actual telescope is 23cm across. This is only a few times larger than the optical instrument Galileo used to explore the heavens over 400 years ago, and BICEP2 may one day rival Galileo in the profundity of its implications for our place in the universe.

BICEP2, to scale - www.bicepkeck.org

]]>Pig WrestlingBad ScienceEquityNew ZealandOpen ScienceSelfCosmologyRichard EastherMon, 07 Apr 2014 10:30:45 +0000http://excursionset.com/blog/2014/4/7/pig-wrestling50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:534110a9e4b00493c4ff568cA side-effect of working on the Big Bang is that I get a fair bit of crank mail (to use the technical term), a few crank phone calls, and even the occasional crank visit. These cranks – or "independent investigators" – usually believe they have solved abiding mysteries in cosmology and theoretical physics, or demolished some key tenet of modern science. Relativity and the Big Bang are popular choices.

The crank community is not a small one. Counting the people who have contacted me directly since I moved back to New Zealand, my country's crank cosmologists clearly outnumber the portion of the local scientific community that works on the evolving universe. (And before you make any jokes I am sure this is true globally but it is easier to conduct the "census" in New Zealand.) In fact, there are few pieces of science so well-settled that you can't find someone to disagree with it. The Flat Earth Society almost perished along with its guiding light Samuel Shenton but it was recently resurrected, and there is an active community that believes the Catholic Church should have stuck to its guns on the geocentric solar system.

Young cosmologists learn fairly quickly that engaging with eccentrics and their pet theories is generally not a good use of their time. My own experience is that "independent investigators" are almost always courteous, decent people. However, they appear to enjoy dissent as much as they enjoy grappling with the deep problems of physics. Consequently, they are rarely overtly upset that they cannot change the opinions of mainstream scientists, and will hold on to their positions in the face of overwhelming evidence to the contrary. The advice I give my students is not to wrestle a pig; you both get muddy, but the pig enjoys it.

Last weekend's NZAS conference saw a thoughtful discussion of how science communicators should respond to heterodox opinions. For scientists, the default position is often the deficit model, which tacitly assumes that once they are provided with the facts, people will naturally align themselves with the position of the scientific community. This is hardly surprising: the lecture is a natural medium for scientists and while it smacks of an argument from authority, it is an authority we respect and are likely to believe we have earned. Unfortunately, this approach does not work on its own; if it did, the Flat Earth Society would long since have died out. Worse yet, in some cases this strategy can actually harden beliefs.

A second theme of the conference was climate: the meeting opened with a screening of The Thin Ice, a film about climate change. Likewise, the recently released IPCC report on the impacts of climate change argues strongly that this is a vital public-policy challenge. If a person turns their back on the Big Bang they are missing out on one of humanity's greatest adventures, but no-one will get hurt. But anti-vaxxers, large chunks of the alt-med crowd and, it increasingly appears, climate denialists are putting human lives and well-being at risk.

Denial has two main approaches. The first is to sow fear, uncertainty and doubt; one can point out that (for instance) climate science is hard and the models are not exact, that is not clear what we should do about climate change even if it exists, and that surely our hospitals and schools provide more pressing and immediate concerns? By contrast, the other approach is one of outright ridicule of science and the rejection of settled, incontestable results. The latter tactic is less common in New Zealand than in the United States, although the Conservative Party's Colin Craig seemed to take a step in this direction when he told an audience that "whether the sun has a hot day or a cold day 'is by far the biggest influence' on the Earth's climate." It's possible that the Dominion Post has mangled Craig's words here, but it is hard to square what he reportedly said with anything that remotely resembles the scientific understanding of the weather, the climate system or solar physics. (Similarly, radio host Mike Hosking appears to live on a planet with different laws of physics to those that apply on Earth.)

The failings of the deficit model of science communication are clear, so identifying effective, alternative strategies is vital, especially at the points where science intersects with public policy. To my eyes, denialism thrives when people see science as an institution with which they have little connection. Deficit-based science communications may inadvertently reinforce barriers between science and this sector of the public. If so, part of the solution lies within ongoing developments in the scientific community. Open Science promises to make science more transparent, enhancing rigour and repeatability. It is easy to say that no-one would eat sausage if they could see it being made, but a sausage-factory with a window is more likely to be a sausage-factory that is spotlessly clean and uses top quality raw materials. Moreover, science is never unanimous, and Open Science may permit a more nuanced understanding of how scientists disagree, and when these disagreements are meaningful. Likewise, embracing diversity among scientists (and our students) will produce a scientific community that looks more like, and can thus fully engage with, the society it's a part of.

I suspect that the solution also involves letting people engage with science with no agenda beyond the excitement of science itself. If – as I saw last weekend – people of all ages and backgrounds can play with ferrofluids, watch a 3D printer at work, imagine driving a rover on Mars, explore an ecosystem in which whales are nourished by plankton, or look a the surface of the sun through a solar telescope, they can get a sense of how science explores, explains and makes use of the natural world. And if people engage with science for the sheer fun of it, they are much more likely to take it seriously when it needs to be heard.

Postscript: During the discussion at the NZAS on the deficit model, I realised it had implications for my own writing on, say, the dangers of Wi-fi or homeopathy. In those pieces, I aimed to focus on how ostensibly evidence-driven institutions, such as journalism or government, deal with these fringe concerns, rather than simply mocking someone for being wrong on the internet. But the question of tone and persuasion is something I'm thinking about.

]]>Science Street Fair...Richard EastherWed, 02 Apr 2014 02:58:22 +0000http://excursionset.com/blog/2014/4/2/science-street-fair50fbc2d2e4b03aa4e2b5f7ac:50fbc2d2e4b03aa4e2b5f7b0:533b252ee4b09f955d5109b0Aucklanders, and those in Auckland this Sunday: MoTAT is holding its inaugural Science Street Fair. This will be a fun, informal event with all sorts of science (and scientists) on display. Not to mention a hovercraft, 3D printing and the "Ask a Scientist" tent...